Sudheer Phani wrote:
> Hello All,
>> I have been encountering some strange problems with the calculation of
> eigen vectors using python. The problem is with the sign of the eigen
> vectors calculated. On Very few occasions the eigen vectors calculated
> using python have an opposite sign than the actual eigenvectors, though
> the magnitude is correct.
Eigenvectors are defined only up to a scalar normalization constant. What do
you mean exactly by opposite sign? If x is an eigenvector for
A*x = s*x (s being the eigenvalue)
then obviously
A*(-x) = s*(-x)
so -x is also an eigenvector with the same eigenvalue (or a.x for a being any
scalar).
Best,
f